Multiple waste pipes

[Inchiquin]

Hi, I would appreciate your opinions on the best way to proceed with the waste pipes in my bathroom. I've attached photos of the current layout inside and outside. As you can see everything at the moment is lead, which I guess means it was done 50 or so years ago. Pipe 1 is from the basin and goes in a straight line through the wall. Pipe 2, as you can see, enters the wall above pipe 1 but exits on the other side of it, so it must twist and turn on its way through the wall. For this reason my first thought was to leave all the lead in place outside for now and just renew everything on the inside. I will be adding a third pipe from a shower, which will come in over the joist on the left at about position 3. My initial idea was to drop this into a junction with pipe 1 just to the right of 3.

However, after searching this forum it seems that it's not a good idea to merge two outlets because of potential blockage feedbacks, and also I discovered after removing the toilet, which was obscuring access to the pipes, that pipe 1 actually runs slightly uphill into the wall and if lifted up to allow the necessary drop would not provide enough height for pipe 3 to drop into the junction.

So I figured that I might as well bore two more holes at positions 5 and 6 for pipes 2 & 3 (blocking off the existing hole for pipe 2), and this would enable me to replace everything, inside and out, with plastic (I might do the toilet outlet pipe at the same time). Does this sound like the most sensible plan? And if so, what's the best way of merging all three pipes at the soil stack?

Thanks in advance
Alan

 

[Inchiquin]

I also meant to add that the obvious best place for the shower pipe to exit would be at position 4, but as you can see from the outside shot, it would hit the soil pipe.

Alan

 

[ktuludays]

Could you replace the lot, new stack and pipes?

 

[Servotech]

Looks a lot like asbestos soil pipe to me.
If it is then it all needs to be replaced with plastic.
1 new stack boss for each of the wastes and all in line connected to the new soil pipe will get the job done all in a workman like manor.

 

[Deleted member 267285]

Bottom half looks like Cast Iron, top section isn’t that visible so could be Cast Iron or could be asbestos. Probably best to rip it out, but you might get away with a drain connector into the branches and renew in pvc.

 

[Inchiquin]

Looks a lot like asbestos soil pipe to me.
If it is then it all needs to be replaced with plastic.
1 new stack boss for each of the wastes and all in line connected to the new soil pipe will get the job done all in a workman like manor.

If it's asbestos it will only be covering the connection between the toilet and the pipe - the pipe itself is lead as it goes through the wall. The connector will be replaced anyway with the toilet, not least because the outlet from the old toilet is about 20mm lower than the pipe so the waste gets trapped in the mouth of the connector trying to run uphill, as you can see from the photo - the plumber obviously didn't understand gravity!

I would very much prefer not to replace the whole stack as that will blow my budget. It's a job I can't do myself and I really wanted to be able to say that I did the entire job on my own, which so far I've managed to do.

Alan

 

[Inchiquin]

Bottom half looks like Cast Iron, top section isn’t that visible so could be Cast Iron or could be asbestos. Probably best to rip it out, but you might get away with a drain connector into the branches and renew in pvc.

Yes the stack itself is cast iron, but the pipes running into it are all lead. The stack isn't really in bad condition - just needs a clean and a coat of Hammerite.

Alan

 

[Deleted member 267285]

I would look at using the drain connector’s then Like this, and then a short boss pipe or something.

 

[Inchiquin]

I would look at using the drain connector’s then Like this, and then a short boss pipe or something.

And feed the three 40mm wastes into it with this perhaps?

FloPlast Push-Fit 4-Boss Single Socket Waste Manifold Black 110mm

Order online at Screwfix.com. Designed to fit a soil stack in the corner of a room. Allows connections to 32mm, 40mm and 50mm waste inlets and helps prevent stack induced siphonage on connecting runs. Four waste connections possible. Single open boss. For use with 32, 40 and 50mm waste pipes...

www.screwfix.com

Alan

 

[Hugh Jaleak]

Manifold needs to be fitted into a vertical section of pipe, it wont be suitable for your application. If you dont want to replace the stack, I'd suggest looking to remove the existing connections into the 4" branches and redoing with new plastic pipework from there. Top branch obviously your WC connection, bottom, fit a waste adapter, such as https://drainagedistribution.co.uk/...-push-fit-soil-waste-adaptor-40mm-40mm-grey-1 and run a pair of 40mm wastes in that. Put bath on one, basin and shower on the other.

 

[Inchiquin]

Manifold needs to be fitted into a vertical section of pipe, it wont be suitable for your application. If you dont want to replace the stack, I'd suggest looking to remove the existing connections into the 4" branches and redoing with new plastic pipework from there. Top branch obviously your WC connection, bottom, fit a waste adapter, such as https://drainagedistribution.co.uk/...-push-fit-soil-waste-adaptor-40mm-40mm-grey-1 and run a pair of 40mm wastes in that. Put bath on one, basin and shower on the other.

Ah, thanks, that was pretty much the sort of thing I was looking for but I hadn't found it. I think I would still need a new hole in the wall though because I could see that replacing the existing pipe that twists and turns with PVC might be difficult, and drilling through 16" of millstone grit will be a PIA (though I think I have the tools for it), so is there any possibility I could join all three together inside? It's a small room so the chances of more than one being used at any one time are very slim. And presumably I could fit NRVs to the shower and basin to prevent any possibility of blockage feedback?

Alan

 

[Hugh Jaleak]

Commoning all 3 isn't usually recommended, but given the situation I can understand why you want to do so. I'd run it in 50mm waste from the point all 3 converge, and I'd provide a Cleaning Eye externally to allow access through the wall and back up the run in the event of an issue.

Basin wont be an issue, it's the shower as the lowest point you need to be concerned about. Have seen the results when a pretty full bath was let go, and the waste couldn't handle the flow. Shower was joined to bath waste before it left the building, Lass had gone into her bedroom to dry her hair, and came back out to find half the bathwater had erupted back through the shower, flooded the room and was dripping through the kitchen light fitting below.....

 

[Inchiquin]

Shower was joined to bath waste before it left the building, Lass had gone into her bedroom to dry her hair, and came back out to find half the bathwater had erupted back through the shower, flooded the room and was dripping through the kitchen light fitting below.....

Yes, that's exactly what I would be worried about! I discovered many years ago what an upstairs leak can do to a lath-and-plaster ceiling below...

Alan